Cables are the lifeblood of our technology. The lack of a single cable can ground an entire system. They’re cheap, commonplace, and indispensable. And like anything critical, humans have found ways to make them better, to optimize them for various conditions. Depending on their application, they’ll be used in everything from high-end home theater equipment to commercial telecommunication networks.
The first step in cable manufacturing is to create the conductors. This is done by drawing a metal wire through a die in most cases. The type of metal used will depend on the desired properties of the conductor. Copper is a popular choice for its good electrical conductivity and resistance to corrosion.
Once the conductors are created, they’re then bundled together and covered with an insulating material. This can be anything from plastic to rubber, depending on the application. For example, coaxial cables use an inner layer of insulation to protect the signal from interference, while Ethernet cables thicker insulation to prevent electrical shorts.
The next step is to cover the insulated conductors with a shield. This can be done in two ways: Either wrapping them with foil or braiding metal wire around the conductors themselves.
Shielded cables are generally more expensive than unshielded ones because of their added protection and shielding effectiveness.
A cross-section of an unshielded Ethernet cable looks like this:
If you’ve ever seen an Ethernet cable and cable production that has a metal clip or connector on one end, then it’s safe to assume that it’s a shielded cable. Unshielded cables use a plastic cap instead of a metal connector for their shielding layer – which offers little to no protection from interference.